The relation of Guru and disciple is only one of many relations which one can have with the Divine, and in this Yoga which aims at a supramental realisation, it is not usual to give it this name; rather, the Divine is regarded as the Source, the living Sun of Light and Knowledge and Consciousness and spiritual realisation and all that one receives is felt as coming from there and the whole being remoulded by the Divine Hand.
This is a greater and more intimate relation than that of the human Guru and disciple, which is more of a limited mental ideal. Nevertheless, if the mind still needs the more familiar mental conception, it can be kept so long as it is needed; only do not let the soul be bound by it and do not let it limit the inflow of other relations with the Divine and larger forms of experience.
Ref: Letters on Himself and Ashram